Top Description Fields Constructors Methods
java.util

public Class TreeSet<E>

extends AbstractSet<E>
implements NavigableSet<E>, Cloneable, Serializable
Class Inheritance
All Implemented Interfaces
java.io.Serializable, java.lang.Cloneable, java.util.NavigableSet, java.util.SortedSet, java.util.SequencedSet, java.util.Set, java.util.Collection, java.lang.Iterable, java.util.SequencedCollection
Type Parameters
<E>
the type of elements maintained by this set
A NavigableSet implementation based on a TreeMap. The elements are ordered using their natural ordering, or by a Comparator provided at set creation time, depending on which constructor is used.

This implementation provides guaranteed log(n) time cost for the basic operations (add, remove and contains).

Note that the ordering maintained by a set (whether or not an explicit comparator is provided) must be consistent with equals if it is to correctly implement the Set interface. (See Comparable or Comparator for a precise definition of consistent with equals.) This is so because the Set interface is defined in terms of the equals operation, but a TreeSet instance performs all element comparisons using its compareTo (or compare) method, so two elements that are deemed equal by this method are, from the standpoint of the set, equal. The behavior of a set is well-defined even if its ordering is inconsistent with equals; it just fails to obey the general contract of the Set interface.

Note that this implementation is not synchronized. If multiple threads access a tree set concurrently, and at least one of the threads modifies the set, it must be synchronized externally. This is typically accomplished by synchronizing on some object that naturally encapsulates the set. If no such object exists, the set should be "wrapped" using the Collections.synchronizedSortedSet method. This is best done at creation time, to prevent accidental unsynchronized access to the set: 

  SortedSet s = Collections.synchronizedSortedSet(new TreeSet(...));

The iterators returned by this class's iterator method are fail-fast: if the set is modified at any time after the iterator is created, in any way except through the iterator's own remove method, the iterator will throw a ConcurrentModificationException. Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future.

Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent modification. Fail-fast iterators throw ConcurrentModificationException on a best-effort basis. Therefore, it would be wrong to write a program that depended on this exception for its correctness: the fail-fast behavior of iterators should be used only to detect bugs.

The addFirst and addLast methods of this class throw UnsupportedOperationException. The encounter order of elements is determined by the comparison method; therefore, explicit positioning is not supported.

This class is a member of the Java Collections Framework.

Author
Josh Bloch
Since
1.2
See Also
Collection, Set, HashSet, Comparable, Comparator, TreeMap

Field Summary

Modifier and TypeField and Description
private transient NavigableMap<E, Object>
m

The backing map.

private static final Object
PRESENT

private static final long
serialVersionUID

Constructor Summary

AccessConstructor and Description
pack-priv
TreeSet(NavigableMap<E, Object> m)

Constructs a set backed by the specified navigable map.

public
TreeSet()

Constructs a new, empty tree set, sorted according to the natural ordering of its elements.

public
TreeSet(Comparator<? super E>
the comparator that will be used to order this set. If null, the natural ordering of the elements will be used.
comparator)

Constructs a new, empty tree set, sorted according to the specified comparator.

public
TreeSet(Collection<? extends E>
collection whose elements will comprise the new set
c)

Constructs a new tree set containing the elements in the specified collection, sorted according to the natural ordering of its elements.

public
TreeSet(SortedSet<E>
sorted set whose elements will comprise the new set
s)

Constructs a new tree set containing the same elements and using the same ordering as the specified sorted set.

Method Summary

Modifier and TypeMethod and Description
public boolean

Returns:

true if this set did not already contain the specified element
add(E
element to be added to this set
e)

Overrides java.util.AbstractCollection.add.

Implements java.util.Set.add, java.util.Collection.add.

Adds the specified element to this set if it is not already present.

public boolean

Returns:

true if this set changed as a result of the call
addAll(Collection<? extends E>
collection containing elements to be added to this set
c)

Overrides java.util.AbstractCollection.addAll.

Implements java.util.Set.addAll, java.util.Collection.addAll.

Adds all of the elements in the specified collection to this set.

public void
addFirst(E
the element to be added
e)

Overrides default java.util.SortedSet.addFirst.

Throws UnsupportedOperationException.

public void
addLast(E
the element to be added.
e)

Overrides default java.util.SortedSet.addLast.

Throws UnsupportedOperationException.

public E
ceiling(E
the value to match
e)

Implements java.util.NavigableSet.ceiling.

Returns the least element in this set greater than or equal to the given element, or null if there is no such element.

public void
clear()

Overrides java.util.AbstractCollection.clear.

Implements java.util.Set.clear, java.util.Collection.clear.

Removes all of the elements from this set.

public Object

Returns:

a shallow copy of this set
clone()

Overrides java.lang.Object.clone.

Returns a shallow copy of this TreeSet instance.

public Comparator<? super E>
comparator()

Implements java.util.SortedSet.comparator.

Returns the comparator used to order the elements in this set, or null if this set uses the natural ordering of its elements.

public boolean

Returns:

true if this set contains the specified element
contains(Object
object to be checked for containment in this set
o)

Overrides java.util.AbstractCollection.contains.

Implements java.util.Set.contains, java.util.Collection.contains.

Returns true if this set contains the specified element.

public Iterator<E>

Returns:

an iterator over the elements in this set in descending order
descendingIterator()

Implements java.util.NavigableSet.descendingIterator.

Returns an iterator over the elements in this set in descending order.

public NavigableSet<E>
descendingSet()

Implements java.util.NavigableSet.descendingSet.

Returns a reverse order view of the elements contained in this set.

public E
first()

Implements java.util.SortedSet.first.

Returns the first (lowest) element currently in this set.

public E
floor(E
the value to match
e)

Implements java.util.NavigableSet.floor.

Returns the greatest element in this set less than or equal to the given element, or null if there is no such element.

public NavigableSet<E>
headSet(E
high endpoint of the returned set
toElement, boolean
true if the high endpoint is to be included in the returned view
inclusive)

Implements java.util.NavigableSet.headSet.

Returns a view of the portion of this set whose elements are less than (or equal to, if inclusive is true) toElement.

public SortedSet<E>
headSet(E
high endpoint (exclusive) of the returned set
toElement)

Implements java.util.NavigableSet.headSet.

Returns a view of the portion of this set whose elements are strictly less than toElement.

public E
higher(E
the value to match
e)

Implements java.util.NavigableSet.higher.

Returns the least element in this set strictly greater than the given element, or null if there is no such element.

public boolean

Returns:

true if this set contains no elements
isEmpty()

Overrides java.util.AbstractCollection.isEmpty.

Implements java.util.Set.isEmpty, java.util.Collection.isEmpty.

Returns true if this set contains no elements.

public Iterator<E>

Returns:

an iterator over the elements in this set in ascending order
iterator()

Implements abstract java.util.AbstractCollection.iterator.

Implements java.util.NavigableSet.iterator, java.util.Set.iterator, java.util.Collection.iterator.

Returns an iterator over the elements in this set in ascending order.

public E
last()

Implements java.util.SortedSet.last.

Returns the last (highest) element currently in this set.

public E
lower(E
the value to match
e)

Implements java.util.NavigableSet.lower.

Returns the greatest element in this set strictly less than the given element, or null if there is no such element.

public E
pollFirst()

Implements java.util.NavigableSet.pollFirst.

Retrieves and removes the first (lowest) element, or returns null if this set is empty (optional operation).

public E
pollLast()

Implements java.util.NavigableSet.pollLast.

Retrieves and removes the last (highest) element, or returns null if this set is empty (optional operation).

private void
readObject(ObjectInputStream s)

Reconstitute the TreeSet instance from a stream (that is, deserialize it).

public boolean

Returns:

true if this set contained the specified element
remove(Object
object to be removed from this set, if present
o)

Overrides java.util.AbstractCollection.remove.

Implements java.util.Set.remove, java.util.Collection.remove.

Removes the specified element from this set if it is present.

public int

Returns:

the number of elements in this set (its cardinality)
size()

Implements abstract java.util.AbstractCollection.size.

Implements java.util.Set.size, java.util.Collection.size.

Returns the number of elements in this set (its cardinality).

public Spliterator<E>

Returns:

a Spliterator over the elements in this set
spliterator()

Overrides default java.util.SortedSet.spliterator, java.util.Set.spliterator, java.util.Collection.spliterator.

Creates a late-binding and fail-fast Spliterator over the elements in this set.

public NavigableSet<E>
subSet(E
low endpoint of the returned set
fromElement, boolean
true if the low endpoint is to be included in the returned view
fromInclusive, E
high endpoint of the returned set
toElement, boolean
true if the high endpoint is to be included in the returned view
toInclusive)

Implements java.util.NavigableSet.subSet.

Returns a view of the portion of this set whose elements range from fromElement to toElement.

public SortedSet<E>
subSet(E
low endpoint (inclusive) of the returned set
fromElement, E
high endpoint (exclusive) of the returned set
toElement)

Implements java.util.NavigableSet.subSet.

Returns a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive.

public NavigableSet<E>
tailSet(E
low endpoint of the returned set
fromElement, boolean
true if the low endpoint is to be included in the returned view
inclusive)

Implements java.util.NavigableSet.tailSet.

Returns a view of the portion of this set whose elements are greater than (or equal to, if inclusive is true) fromElement.

public SortedSet<E>
tailSet(E
low endpoint (inclusive) of the returned set
fromElement)

Implements java.util.NavigableSet.tailSet.

Returns a view of the portion of this set whose elements are greater than or equal to fromElement.

private void
writeObject(ObjectOutputStream s)

Save the state of the TreeSet instance to a stream (that is, serialize it).

Inherited from java.util.AbstractSet:
equalshashCoderemoveAll

Field Detail

mback to summary
private transient NavigableMap<E, Object> m

The backing map.

PRESENTback to summary
private static final Object PRESENT
serialVersionUIDback to summary
private static final long serialVersionUID
Annotations
@Serial

Constructor Detail

TreeSetback to summary
pack-priv TreeSet(NavigableMap<E, Object> m)

Constructs a set backed by the specified navigable map.

TreeSetback to summary
public TreeSet()

Constructs a new, empty tree set, sorted according to the natural ordering of its elements. All elements inserted into the set must implement the Comparable interface. Furthermore, all such elements must be mutually comparable: e1.compareTo(e2) must not throw a ClassCastException for any elements e1 and e2 in the set. If the user attempts to add an element to the set that violates this constraint (for example, the user attempts to add a string element to a set whose elements are integers), the add call will throw a ClassCastException.

TreeSetback to summary
public TreeSet(Comparator<? super E> comparator)

Constructs a new, empty tree set, sorted according to the specified comparator. All elements inserted into the set must be mutually comparable by the specified comparator: comparator.compare(e1, e2) must not throw a ClassCastException for any elements e1 and e2 in the set. If the user attempts to add an element to the set that violates this constraint, the add call will throw a ClassCastException.

Parameters
comparator:Comparator<? super E>

the comparator that will be used to order this set. If null, the natural ordering of the elements will be used.

TreeSetback to summary
public TreeSet(Collection<? extends E> c)

Constructs a new tree set containing the elements in the specified collection, sorted according to the natural ordering of its elements. All elements inserted into the set must implement the Comparable interface. Furthermore, all such elements must be mutually comparable: e1.compareTo(e2) must not throw a ClassCastException for any elements e1 and e2 in the set.

Parameters
c:Collection<? extends E>

collection whose elements will comprise the new set

Exceptions
ClassCastException:
if the elements in c are not Comparable, or are not mutually comparable
NullPointerException:
if the specified collection is null
TreeSetback to summary
public TreeSet(SortedSet<E> s)

Constructs a new tree set containing the same elements and using the same ordering as the specified sorted set.

Parameters
s:SortedSet<E>

sorted set whose elements will comprise the new set

Exceptions
NullPointerException:
if the specified sorted set is null

Method Detail

addback to summary
public boolean add(E e)

Overrides java.util.AbstractCollection.add.

Implements java.util.Set.add, java.util.Collection.add.

Adds the specified element to this set if it is not already present. More formally, adds the specified element e to this set if the set contains no element e2 such that Objects.equals(e, e2). If this set already contains the element, the call leaves the set unchanged and returns false.

Parameters
e:E

element to be added to this set

Returns:boolean

true if this set did not already contain the specified element

Exceptions
ClassCastException:
if the specified object cannot be compared with the elements currently in this set
NullPointerException:
if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements
addAllback to summary
public boolean addAll(Collection<? extends E> c)

Overrides java.util.AbstractCollection.addAll.

Implements java.util.Set.addAll, java.util.Collection.addAll.

Adds all of the elements in the specified collection to this set.

Parameters
c:Collection<? extends E>

collection containing elements to be added to this set

Returns:boolean

true if this set changed as a result of the call

Exceptions
ClassCastException:
if the elements provided cannot be compared with the elements currently in the set
NullPointerException:
if the specified collection is null or if any element is null and this set uses natural ordering, or its comparator does not permit null elements
addFirstback to summary
public void addFirst(E e)

Overrides default java.util.SortedSet.addFirst.

Throws UnsupportedOperationException. The encounter order induced by this set's comparison method determines the position of elements, so explicit positioning is not supported.

Parameters
e:E

Doc from java.util.SequencedCollection.addFirst.

the element to be added

Exceptions
UnsupportedOperationException:
always
Since
21
addLastback to summary
public void addLast(E e)

Overrides default java.util.SortedSet.addLast.

Throws UnsupportedOperationException. The encounter order induced by this set's comparison method determines the position of elements, so explicit positioning is not supported.

Parameters
e:E

Doc from java.util.SequencedCollection.addLast.

the element to be added.

Exceptions
UnsupportedOperationException:
always
Since
21
ceilingback to summary
public E ceiling(E e)

Implements java.util.NavigableSet.ceiling.

Doc from java.util.NavigableSet.ceiling.

Returns the least element in this set greater than or equal to the given element, or null if there is no such element.

Parameters
e:E

the value to match

Returns:E

the least element greater than or equal to e, or null if there is no such element

Exceptions
ClassCastException:
if the specified element cannot be compared with the elements currently in the set
NullPointerException:
if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements
Since
1.6
clearback to summary
public void clear()

Overrides java.util.AbstractCollection.clear.

Implements java.util.Set.clear, java.util.Collection.clear.

Removes all of the elements from this set. The set will be empty after this call returns.

cloneback to summary
public Object clone()

Overrides java.lang.Object.clone.

Returns a shallow copy of this TreeSet instance. (The elements themselves are not cloned.)

Returns:Object

a shallow copy of this set

Annotations
@SuppressWarnings:unchecked
comparatorback to summary
public Comparator<? super E> comparator()

Implements java.util.SortedSet.comparator.

Doc from java.util.SortedSet.comparator.

Returns the comparator used to order the elements in this set, or null if this set uses the natural ordering of its elements.

Returns:Comparator<? super E>

the comparator used to order the elements in this set, or null if this set uses the natural ordering of its elements

containsback to summary
public boolean contains(Object o)

Overrides java.util.AbstractCollection.contains.

Implements java.util.Set.contains, java.util.Collection.contains.

Returns true if this set contains the specified element. More formally, returns true if and only if this set contains an element e such that Objects.equals(o, e).

Parameters
o:Object

object to be checked for containment in this set

Returns:boolean

true if this set contains the specified element

Exceptions
ClassCastException:
if the specified object cannot be compared with the elements currently in the set
NullPointerException:
if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements
descendingIteratorback to summary
public Iterator<E> descendingIterator()

Implements java.util.NavigableSet.descendingIterator.

Returns an iterator over the elements in this set in descending order.

Returns:Iterator<E>

an iterator over the elements in this set in descending order

Since
1.6
descendingSetback to summary
public NavigableSet<E> descendingSet()

Implements java.util.NavigableSet.descendingSet.

Doc from java.util.NavigableSet.descendingSet.

Returns a reverse order view of the elements contained in this set. The descending set is backed by this set, so changes to the set are reflected in the descending set, and vice-versa. If either set is modified while an iteration over either set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined.

The returned set has an ordering equivalent to Collections.reverseOrder(comparator()). The expression s.descendingSet().descendingSet() returns a view of s essentially equivalent to s.

Returns:NavigableSet<E>

a reverse order view of this set

Since
1.6
firstback to summary
public E first()

Implements java.util.SortedSet.first.

Doc from java.util.SortedSet.first.

Returns the first (lowest) element currently in this set.

Returns:E

the first (lowest) element currently in this set

Exceptions
NoSuchElementException:
if this set is empty
floorback to summary
public E floor(E e)

Implements java.util.NavigableSet.floor.

Doc from java.util.NavigableSet.floor.

Returns the greatest element in this set less than or equal to the given element, or null if there is no such element.

Parameters
e:E

the value to match

Returns:E

the greatest element less than or equal to e, or null if there is no such element

Exceptions
ClassCastException:
if the specified element cannot be compared with the elements currently in the set
NullPointerException:
if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements
Since
1.6
headSetback to summary
public NavigableSet<E> headSet(E toElement, boolean inclusive)

Implements java.util.NavigableSet.headSet.

Doc from java.util.NavigableSet.headSet.

Returns a view of the portion of this set whose elements are less than (or equal to, if inclusive is true) toElement. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

Parameters
toElement:E

high endpoint of the returned set

inclusive:boolean

true if the high endpoint is to be included in the returned view

Returns:NavigableSet<E>

a view of the portion of this set whose elements are less than (or equal to, if inclusive is true) toElement

Exceptions
ClassCastException:
if toElement is not compatible with this set's comparator (or, if the set has no comparator, if toElement does not implement Comparable). Implementations may, but are not required to, throw this exception if toElement cannot be compared to elements currently in the set.
NullPointerException:
if toElement is null and this set uses natural ordering, or its comparator does not permit null elements
IllegalArgumentException:
if this set itself has a restricted range, and toElement lies outside the bounds of the range
Since
1.6
headSetback to summary
public SortedSet<E> headSet(E toElement)

Implements java.util.NavigableSet.headSet.

Doc from java.util.NavigableSet.headSet.

Returns a view of the portion of this set whose elements are strictly less than toElement. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

Equivalent to headSet(toElement, false).

Parameters
toElement:E

Doc from java.util.SortedSet.headSet.

high endpoint (exclusive) of the returned set

Returns:SortedSet<E>

Doc from java.util.SortedSet.headSet.

a view of the portion of this set whose elements are strictly less than toElement

Exceptions
ClassCastException:
if toElement is not compatible with this set's comparator (or, if the set has no comparator, if toElement does not implement Comparable). Implementations may, but are not required to, throw this exception if toElement cannot be compared to elements currently in the set.
NullPointerException:
if toElement is null and this set uses natural ordering, or its comparator does not permit null elements
IllegalArgumentException:
if this set itself has a restricted range, and toElement lies outside the bounds of the range
higherback to summary
public E higher(E e)

Implements java.util.NavigableSet.higher.

Doc from java.util.NavigableSet.higher.

Returns the least element in this set strictly greater than the given element, or null if there is no such element.

Parameters
e:E

the value to match

Returns:E

the least element greater than e, or null if there is no such element

Exceptions
ClassCastException:
if the specified element cannot be compared with the elements currently in the set
NullPointerException:
if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements
Since
1.6
isEmptyback to summary
public boolean isEmpty()

Overrides java.util.AbstractCollection.isEmpty.

Implements java.util.Set.isEmpty, java.util.Collection.isEmpty.

Returns true if this set contains no elements.

Returns:boolean

true if this set contains no elements

iteratorback to summary
public Iterator<E> iterator()

Implements abstract java.util.AbstractCollection.iterator.

Implements java.util.NavigableSet.iterator, java.util.Set.iterator, java.util.Collection.iterator.

Returns an iterator over the elements in this set in ascending order.

Returns:Iterator<E>

an iterator over the elements in this set in ascending order

lastback to summary
public E last()

Implements java.util.SortedSet.last.

Doc from java.util.SortedSet.last.

Returns the last (highest) element currently in this set.

Returns:E

the last (highest) element currently in this set

Exceptions
NoSuchElementException:
if this set is empty
lowerback to summary
public E lower(E e)

Implements java.util.NavigableSet.lower.

Doc from java.util.NavigableSet.lower.

Returns the greatest element in this set strictly less than the given element, or null if there is no such element.

Parameters
e:E

the value to match

Returns:E

the greatest element less than e, or null if there is no such element

Exceptions
ClassCastException:
if the specified element cannot be compared with the elements currently in the set
NullPointerException:
if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements
Since
1.6
pollFirstback to summary
public E pollFirst()

Implements java.util.NavigableSet.pollFirst.

Doc from java.util.NavigableSet.pollFirst.

Retrieves and removes the first (lowest) element, or returns null if this set is empty (optional operation).

Returns:E

the first element, or null if this set is empty

Since
1.6
pollLastback to summary
public E pollLast()

Implements java.util.NavigableSet.pollLast.

Doc from java.util.NavigableSet.pollLast.

Retrieves and removes the last (highest) element, or returns null if this set is empty (optional operation).

Returns:E

the last element, or null if this set is empty

Since
1.6
readObjectback to summary
private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException

Reconstitute the TreeSet instance from a stream (that is, deserialize it).

Annotations
@Serial
removeback to summary
public boolean remove(Object o)

Overrides java.util.AbstractCollection.remove.

Implements java.util.Set.remove, java.util.Collection.remove.

Removes the specified element from this set if it is present. More formally, removes an element e such that Objects.equals(o, e), if this set contains such an element. Returns true if this set contained the element (or equivalently, if this set changed as a result of the call). (This set will not contain the element once the call returns.)

Parameters
o:Object

object to be removed from this set, if present

Returns:boolean

true if this set contained the specified element

Exceptions
ClassCastException:
if the specified object cannot be compared with the elements currently in this set
NullPointerException:
if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements
sizeback to summary
public int size()

Implements abstract java.util.AbstractCollection.size.

Implements java.util.Set.size, java.util.Collection.size.

Returns the number of elements in this set (its cardinality).

Returns:int

the number of elements in this set (its cardinality)

spliteratorback to summary
public Spliterator<E> spliterator()

Overrides default java.util.SortedSet.spliterator, java.util.Set.spliterator, java.util.Collection.spliterator.

Creates a late-binding and fail-fast Spliterator over the elements in this set.

The Spliterator reports Spliterator#SIZED, Spliterator#DISTINCT, Spliterator#SORTED, and Spliterator#ORDERED. Overriding implementations should document the reporting of additional characteristic values.

The spliterator's comparator (see java.util.Spliterator#getComparator()) is null if the tree set's comparator (see comparator()) is null. Otherwise, the spliterator's comparator is the same as or imposes the same total ordering as the tree set's comparator.

Returns:Spliterator<E>

a Spliterator over the elements in this set

Since
1.8
subSetback to summary
public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive)

Implements java.util.NavigableSet.subSet.

Doc from java.util.NavigableSet.subSet.

Returns a view of the portion of this set whose elements range from fromElement to toElement. If fromElement and toElement are equal, the returned set is empty unless fromInclusive and toInclusive are both true. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

Parameters
fromElement:E

low endpoint of the returned set

fromInclusive:boolean

true if the low endpoint is to be included in the returned view

toElement:E

high endpoint of the returned set

toInclusive:boolean

true if the high endpoint is to be included in the returned view

Returns:NavigableSet<E>

a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive

Exceptions
ClassCastException:
if fromElement and toElement cannot be compared to one another using this set's comparator (or, if the set has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if fromElement or toElement cannot be compared to elements currently in the set.
NullPointerException:
if fromElement or toElement is null and this set uses natural ordering, or its comparator does not permit null elements
IllegalArgumentException:
if fromElement is greater than toElement; or if this set itself has a restricted range, and fromElement or toElement lies outside the bounds of the range.
Since
1.6
subSetback to summary
public SortedSet<E> subSet(E fromElement, E toElement)

Implements java.util.NavigableSet.subSet.

Doc from java.util.NavigableSet.subSet.

Returns a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive. (If fromElement and toElement are equal, the returned set is empty.) The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

Equivalent to subSet(fromElement, true, toElement, false).

Parameters
fromElement:E

Doc from java.util.SortedSet.subSet.

low endpoint (inclusive) of the returned set

toElement:E

Doc from java.util.SortedSet.subSet.

high endpoint (exclusive) of the returned set

Returns:SortedSet<E>

Doc from java.util.SortedSet.subSet.

a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive

Exceptions
ClassCastException:
if fromElement and toElement cannot be compared to one another using this set's comparator (or, if the set has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if fromElement or toElement cannot be compared to elements currently in the set.
NullPointerException:
if fromElement or toElement is null and this set uses natural ordering, or its comparator does not permit null elements
IllegalArgumentException:
if fromElement is greater than toElement; or if this set itself has a restricted range, and fromElement or toElement lies outside the bounds of the range
tailSetback to summary
public NavigableSet<E> tailSet(E fromElement, boolean inclusive)

Implements java.util.NavigableSet.tailSet.

Doc from java.util.NavigableSet.tailSet.

Returns a view of the portion of this set whose elements are greater than (or equal to, if inclusive is true) fromElement. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

Parameters
fromElement:E

low endpoint of the returned set

inclusive:boolean

true if the low endpoint is to be included in the returned view

Returns:NavigableSet<E>

a view of the portion of this set whose elements are greater than or equal to fromElement

Exceptions
ClassCastException:
if fromElement is not compatible with this set's comparator (or, if the set has no comparator, if fromElement does not implement Comparable). Implementations may, but are not required to, throw this exception if fromElement cannot be compared to elements currently in the set.
NullPointerException:
if fromElement is null and this set uses natural ordering, or its comparator does not permit null elements
IllegalArgumentException:
if this set itself has a restricted range, and fromElement lies outside the bounds of the range
Since
1.6
tailSetback to summary
public SortedSet<E> tailSet(E fromElement)

Implements java.util.NavigableSet.tailSet.

Doc from java.util.NavigableSet.tailSet.

Returns a view of the portion of this set whose elements are greater than or equal to fromElement. The returned set is backed by this set, so changes in the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.

The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.

Equivalent to tailSet(fromElement, true).

Parameters
fromElement:E

Doc from java.util.SortedSet.tailSet.

low endpoint (inclusive) of the returned set

Returns:SortedSet<E>

Doc from java.util.SortedSet.tailSet.

a view of the portion of this set whose elements are greater than or equal to fromElement

Exceptions
ClassCastException:
if fromElement is not compatible with this set's comparator (or, if the set has no comparator, if fromElement does not implement Comparable). Implementations may, but are not required to, throw this exception if fromElement cannot be compared to elements currently in the set.
NullPointerException:
if fromElement is null and this set uses natural ordering, or its comparator does not permit null elements
IllegalArgumentException:
if this set itself has a restricted range, and fromElement lies outside the bounds of the range
writeObjectback to summary
private void writeObject(ObjectOutputStream s) throws IOException

Save the state of the TreeSet instance to a stream (that is, serialize it).

Annotations
@Serial
Serial data
Emits the comparator used to order this set, or null if it obeys its elements' natural ordering (Object), followed by the size of the set (the number of elements it contains) (int), followed by all of its elements (each an Object) in order (as determined by the set's Comparator, or by the elements' natural ordering if the set has no Comparator).